This invention relates to storing information about the contents of a consumable accessory unit in a storage device associated with the unit, and then taking some action related to the unit or its contents based on the stored information.
It is known to incorporate a read only memory (ROM) into a container for storing information. In Coffee et al., U.S. Pat. No. 4,580,721, issued Apr. 8, 1986, the container holds a pesticide, and the ROM stores the following information (col. 13, lines 31-64, and Table II): a "handshake security code" to restrict usage of the container; "acceptable flow rates" for the pesticide; a "voltage" setting for an electrostatic sprayer for the pesticide; the "container size;" the "chemical type" of the pesticide; and "the formulation date." Coffee also uses a programmable ROM in the container to hold and update a value representing the "liquid quantity" in the container. Coffee s container is used with spray machinery that includes electronics which control the spraying of the pesticide based on the information in the ROM.